package Solutiong1;

   class s1 {
        public boolean chkPalindrome(ListNode A) {
            if(A==null){
                return true;
            }
            ListNode slow=A;
            ListNode fast=A;
            while(fast!=null&&fast.next!=null){
                fast=fast.next.next;
                slow=slow.next;
            }
            ListNode cur=slow.next;
            while(cur!=null){
                ListNode curN=cur.next;
                cur.next=slow;
                slow=cur;
                cur=curN;
            }
            while(A!=slow){
                if(A.val!=slow.val){
                    return false;
                }
                if(A.next==slow){
                    return true;
                }
                A=A.next;
                slow=slow.next;
            }
            return true;
        }

       public static void main(String[] args) {

       }
    }
